AI Wander & Barker (#286)

* Retrofit the AI system with new IoC features.
Fixed bug with turret rotation.

* Added new AI WanderProcessor, and it works.

* RNG walking directions are a bit more random now.

* Wander now actually uses the MoverSystem to move.
Wander now talks when he reaches his destination.

* Adds a new Static Barker AI for vending machines, so that they periodically advertise their brand.

* Barker now says some generic slogans.
Misc bug cleanup.

* Removed useless UsedImplicitly attribute from AI dependencies, suppressed unused variable warnings instead.

Content.Server/AI/StaticBarkerProcessor.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Content.Server.Interfaces.Chat;
+using JetBrains.Annotations;
+using Robust.Server.AI;
+using Robust.Shared.Interfaces.Timing;
+using Robust.Shared.IoC;
+using Robust.Shared.Utility;
+
+namespace Content.Server.AI
+{
+    /// <summary>
+    /// Designed for a a stationary entity that regularly advertises things (vending machine).
+    /// </summary>
+    [AiLogicProcessor("StaticBarker")]
+    class StaticBarkerProcessor : AiLogicProcessor
+    {
+#pragma warning disable 649
+        [Dependency] private readonly IGameTiming _timeMan;
+        [Dependency] private readonly IChatManager _chatMan;
+#pragma warning restore 649
+
+        private static readonly TimeSpan MinimumDelay = TimeSpan.FromSeconds(15);
+        private TimeSpan _nextBark;
+
+
+        private static List<string> slogans = new List<string>
+        {
+            "Come try my great products today!",
+            "More value for the way you live.",
+            "Quality you'd expect at prices you wouldn't.",
+            "The right stuff. The right price.",
+        };
+
+        public override void Update(float frameTime)
+        {
+            if(_timeMan.CurTime < _nextBark)
+                return;
+            
+            var rngState = GenSeed();
+            _nextBark = _timeMan.CurTime + MinimumDelay + TimeSpan.FromSeconds(Random01(ref rngState) * 10);
+
+            var pick = (int)Math.Round(Random01(ref rngState) * (slogans.Count - 1));
+            _chatMan.EntitySay(SelfEntity, slogans[pick]);
+        }
+
+        private uint GenSeed()
+        {
+            return RotateRight((uint)_timeMan.CurTick.GetHashCode(), 11) ^ (uint)SelfEntity.Uid.GetHashCode();
+        }
+
+        private uint RotateRight(uint n, int s)
+        {
+            return (n << (32 - s)) | (n >> s);
+        }
+
+        private float Random01(ref uint state)
+        {
+            DebugTools.Assert(state != 0);
+
+            //xorshift32
+            state ^= state << 13;
+            state ^= state >> 17;
+            state ^= state << 5;
+            return state / (float)uint.MaxValue;
+        }
+    }
+}